On March 11, 1989, a Champion 7KCAB (registration N12208) operated by Gary A. Bates was involved in an aviation accident near Steubenville, OH. Investigators recorded the probable cause as: THE RUDDER CONTROL CABLE FAILED WHICH RENDERED THE CONTROL SURFACE INOPERATIVE. THE LOSS OF RUDDER PRECLUDED THE PILOT FROM MAINTAINING DIRECTIONAL CONTROL AFTER LANDING. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During an aerobatic flight, a rudder control cable failed, causing complete loss of rudder control. The pilot returned and landed, but lost directional control after touchdown, departing the runway and colliding with trees. Examination revealed cable failure with electrical arc damage.
Incident Overview
While performing aerobatic maneuvers, the pilot of a single-engine airplane lost all rudder control when the control cable failed. The pilot managed to fly back to the departure airport and initiate a landing. However, after the wheels touched down, the pilot was unable to steer the airplane, resulting in a loss of directional control. The aircraft departed the paved surface of the runway and continued into an adjacent area before colliding with trees.
Examination of the Rudder Control System
A thorough inspection of the wreckage focused on the rudder control system. Investigators found that the rudder control cable had separated. Examination of the broken cable ends under magnification indicated that the fracture faces on the majority of the individual strands exhibited characteristics typical of electrical arcing. The location of the failed cable was near two access panels that provide maintenance entry to the control cable routing area.
Determination of the Failure Mechanism
Despite the physical evidence pointing to an electrical arc as the likely cause of the strand fractures, the investigation was unable to identify the specific origin of the electrical current or the precise sequence of events that led to the cable's failure. Consequently, the exact cause of the rudder control cable failure remains undetermined.